EP0579236B1 - Schaltung zur Detektion von phasenumgetasteten Impulsen - Google Patents

Schaltung zur Detektion von phasenumgetasteten Impulsen Download PDF

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Publication number
EP0579236B1
EP0579236B1 EP93111402A EP93111402A EP0579236B1 EP 0579236 B1 EP0579236 B1 EP 0579236B1 EP 93111402 A EP93111402 A EP 93111402A EP 93111402 A EP93111402 A EP 93111402A EP 0579236 B1 EP0579236 B1 EP 0579236B1
Authority
EP
European Patent Office
Prior art keywords
circuit
pulse
signal
voltage
keyed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP93111402A
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English (en)
French (fr)
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EP0579236A1 (de
Inventor
Kazunori C/O Nec Corporation Nishijima
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
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NEC Corp
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Filing date
Publication date
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Publication of EP0579236A1 publication Critical patent/EP0579236A1/de
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Publication of EP0579236B1 publication Critical patent/EP0579236B1/de
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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
    • H03K5/01—Shaping pulses
    • H03K5/04—Shaping pulses by increasing duration; by decreasing duration
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
    • H03K5/01—Shaping pulses
    • H03K5/08—Shaping pulses by limiting; by thresholding; by slicing, i.e. combined limiting and thresholding

Definitions

  • the present invention relates to a pulse sensor circuit, and in particular, to a keyed automatic frequency control (AFC) pulse sensor circuit for use in a hi-vision satellite broadcast receiver.
  • AFC automatic frequency control
  • each of first and second local oscillators produces a stable frequency. Namely, a frequency change in a second intermediate frequency is required to be in a range of ⁇ 500 kHz for a variation of ⁇ 2 MHz in a frequency of input signal. When the frequency variation is beyond the range, the operating frequency shifts from a central frequency of such a related circuit as a second intermediate frequency band-pass filter (BPF), a tuning circuit, or an FM demodulator.
  • BPF second intermediate frequency band-pass filter
  • the distortion is increased in a differential gain and a differential phase; moreover, the signal-to-noise (SN) ratio may possibly be lowered, which leads to deterioration of the reception quality.
  • AFC automatic frequency controller
  • the AFC circuit is used to control the local oscillation frequency and to automatically correct the variation in the input frequency, thereby keeping an appropriate intermediate frequency.
  • the circuit includes a first intermediate frequency (IF) amplifier 31, a frequency converter 32, a band-pass filter 33, an automatic gain controller (AGC) 34, a limiter circuit 35, an FM demodulator 36, an integration circuit 38, and a local oscillator 39.
  • IF intermediate frequency
  • AGC automatic gain controller
  • This voltage 37 is fed to the integrating circuit 38 such that a modulated frequency component is removed therefrom so as to supply a resultant signal to a varactor diode of the oscillator circuit 39.
  • a control loop to achieve an automatic frequency control.
  • a keyed pulse 41 is received from a decoder of a multiple sub-Nyquist sampling encoding (MUSE) system.
  • the pulse 41 is delivered to a sample holding circuit 43 such that an FM demodulation voltage from an FM demodulator 36 is held as a sample by the circuit 43 so as to obtain a mean value of the FM modulation voltage, thereby applying the attained FM modulation voltage to a varactor diode of a local oscillator 39.
  • SW switch 44 to select the FM modulation voltage or the voltage obtained by processing the FM modulation voltage through the sample holding circuit 43 according to the keyed pulse 41 and a keyed pulse sensor 42 to control the switch 44 depending on the keyed pulse 41.
  • the keyed pulse sensing circuit 42 of the prior art includes, for example, a capacitor 13 connected to an input terminal 12, a pulse amplifier 10 including resistors 14 and 15 and an inverter 16, and a one-shot multi-vibrator 11 as shown in Fig. 3.
  • the pulse amplifier 10 is connected to a preceding stage of the multivibrator 11. This is because the keyed pulse has a low output voltage 0.5 Vpp and hence an output of at least 5 Vpp is required to drive a multivibrator 11 in a subsequent stage.
  • the output from the multivibrator 11 is kept remained at 5 V when the keyed pulse is successively supplied thereto. However, in a case where only one keyed pulse is inputted thereto, a time constant of the multivibrator 11 is adjusted so as to produce a pulse having a time width exceeding a period of the keyed pulse.
  • Figs. 4A and 4B specifically show relationships between the input keyed pulses and the output from the one-shot multivibrator.
  • CMOS-IC complementary metal-oxide semiconductor integrated circuit
  • GB-A-2 189 956 discloses an isolation amplifier, which incorporates a circuit for providing an output pulse whose duration and interval are identical to those of the input signal. This invention cannot be used with the application for which the present invention is intended because its circuit outputs a narrow pulse if the input pulse width is narrow.
  • a pulse sensor circuit including a differentiation circuit for receiving a pulse signal and for producing a differentiated signal therefrom, a dc amplifier for amplifying the differentiated signal, and a window comparator for receiving a signal created from the dc amplifier and setting a central voltage of a blind sector to a dc voltage of the dc amplifier in a signal-free state where the amplifier is not outputting any amplifier signal to the comparator.
  • a keyed pulse is supplied to a differentiation circuit having a time constant sufficiently larger than a pulse width of the keyed pulse so as to generate a sawtooth wave signal.
  • the obtained signal is then fed to the window comparator for a comparison thereof.
  • the keyed pulse sensor can be formed only of analog circuits such as a differentiation circuit and a window comparator.
  • Fig. 5 shows the circuit constitution of the pulse sensor, which includes a differentiation circuit 1, a dc amplifier 2, and a window comparator 3.
  • the circuit 1 includes a capacitor C 1 , a resistor R 1 , and a bias voltage source V B1 .
  • the dc amplifier 2 includes an operation amplifier 4 and resistors R 2 and R 3 .
  • the circuit 3 includes comparators 5 and 6, an OR gate 7, and voltage sources V ref1 and V ref2 .
  • the circuit 1 when a keyed pulse 101 shown in Fig. 6A is supplied to an input terminal 8, the circuit 1 produces a differentiation output 201 of Fig. 6B.
  • a time constant developed by the resistor R 1 and the capacitor C 1 is sufficiently greater than a time width of the pulse 101.
  • Amplifying the output signal 201 by the amplifier 2 there is created an output 301 shown in Fig. 6C.
  • the obtained signal 301 is delivered as an input to the comparator 3.
  • the reference voltages V ref1 and V ref2 respectively of the comparators 5 and 6 are set as shown in Fig.
  • a width of the blind sector of the comparator 3 is represented by a range of 2Va centered on the dc voltage of the output signal 301 from the amplifier in the signal-free state where the amplifier 2 is not producing the amplified output.
  • the comparator 3 resultantly produces an output 401 of Fig. 6D.
  • the differentiating circuit 1 generates an output 202 of Fig. 7B.
  • the amplifier 2 produces an output 302 as shown in Fig. 7C.
  • the window comparator 3 creates an output signal 402 of Fig. 7D, which is kept remained at a high (H) level.
  • the comparator 3 continuously produces an H-level output signal even in a interval of time in which the keyed pulse is absent. Namely, it is assumed that the keyed pulse is sensed even in such an interval.
  • the obtained signal is fed as a pulse sense signal from an output terminal 9 to an external device.
  • Fig. 8 shows an alternative embodiment of the pulse sensor in accordance with the present invention.
  • the sensor circuit includes an integration circuit 22, a dc amplifier 23, and a window comparator 24.
  • the circuit 22 is different from that of Fig. 1 including the capacitor C 1 and the resistor R 1 . Namely, this sensor includes a capacitor C 2 , a resistor R 4 , an operation amplifier 25, and the bias voltage source V B2 .
  • the amplifier 23 includes an operation amplifier 26 and resistor R 5 and R 6 .
  • the comparator circuit 24 includes comparators 27 and 28, and OR gate 29, and voltage sources V ref1 and V ref2 . Operation of the system is identical to that shown in Fig. 5 and hence description thereof will be avoided.
  • the pulse sensor circuit in accordance with the present invention simply includes analog circuits to sense keyed pulses. Consequently, the number of necessary elements thereof can be decreased. Moreover, when the pulse sensor of the present invention is to be incorporated in, for example, an FM modulator circuit, there can be easily fabricated an integrated circuit thereof.

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Television Receiver Circuits (AREA)
  • Circuits Of Receivers In General (AREA)
  • Manipulation Of Pulses (AREA)

Claims (4)

  1. Impuls-Sensorschaltung für getastete Impulse (keyed pulse sensor circuit) zur Lieferung eines Ausgangsimpulses, dessen Dauer länger ist als die Zeitdauer eines Eingangsimpulssignals, wobei die Schaltung folgendes aufweist:
    eine Differenzierschaltvorrichtung (1), die auf das Eingangsimpulssignal anspricht, um ein Differenzierungssignal zu erzeugen;
    eine Gleichspannungsverstärkervorrichtung (4) zum Verstärken des Differenzierungssignals; und
    eine Fensterdetektorvorrichtung (3) zum Empfangen eines Ausgangssignals von der Gleichspannungsverstärkervorrichtung als ein Eingangssignal und zum Einstellen einer zentralen Spannung eines Blindsektors davon auf eine Gleichspannung von der Gleichspannungsverstärkervorrichtung in einem signalfreien Zustand, in welchem die Fensterdetektorvorrichtung (3) keinen Ausgangsimpuls erzeugt,
    wobei die Differenzierungsschaltung (1) folgendes aufweist:
    einen Kondensator (C1) und einen Widerstand (R1), deren Zeitkonstante größer ist als die Zeitspanne des Eingangsimpulssignals.
  2. Schaltung nach Anspruch 1, bei der die Fensterdetektorvorrichtung zwei Differenzverstärkerschaltungen und ein ODER-Glied aufweist.
  3. AFC-Schaltung, die folgendes aufweist:
    eine FM-Modulatorschaltung;
    eine Abtast-Halte-Schaltung zum Halten einer FM-Demodulations-Spannung von der FM-Modulatorschaltung als einen Abtastwert durch einen getasteten Impuls (keyed pulse) von einem Decoder eines Mehrfach-Sub-Nyquist-Abtastungs-Codier-Systems (MUSE-System); und
    einen Schalter zum Auswählen der FM-Modulationsspannung von der FM-Modulatorschaltung oder der durch Verarbeitung der FM-Modulationsspannung durch die Abtast-Halte-Schaltung erhaltenen Spannung, wobei die AFC-Schaltung weiterhin folgendes aufweist:
    eine Impuls-Sensorschaltung für getastete Impulse (keyed pulse sensor circuit) nach Anspruch 1.
  4. Schaltung nach Anspruch 3, bei der die Fensterdetektorvorrichtung zwei Differenzverstärkerschaltungen und ein ODER-Glied aufweist.
EP93111402A 1992-07-15 1993-07-15 Schaltung zur Detektion von phasenumgetasteten Impulsen Expired - Lifetime EP0579236B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP188034/92 1992-07-15
JP4188034A JP2845253B2 (ja) 1992-07-15 1992-07-15 キードパルス検出回路

Publications (2)

Publication Number Publication Date
EP0579236A1 EP0579236A1 (de) 1994-01-19
EP0579236B1 true EP0579236B1 (de) 1998-10-07

Family

ID=16216514

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93111402A Expired - Lifetime EP0579236B1 (de) 1992-07-15 1993-07-15 Schaltung zur Detektion von phasenumgetasteten Impulsen

Country Status (4)

Country Link
US (1) US5559836A (de)
EP (1) EP0579236B1 (de)
JP (1) JP2845253B2 (de)
DE (1) DE69321410T2 (de)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2289177B (en) * 1994-04-29 1998-04-15 Plessey Semiconductors Ltd Receiver arrangement
US5831456A (en) * 1997-04-28 1998-11-03 Marvell Technology Group, Ltd. Apparatus and method for transient suppression in synchronous data detection systems
USRE37751E1 (en) * 1997-04-28 2002-06-18 Marvell International Ltd. Apparatus and method for transient suppression in synchronous data detection systems
US6219107B1 (en) * 1997-12-22 2001-04-17 Texas Instruments Incorporated Automatic AGC bias voltage calibration in a video decoder
US6192089B1 (en) * 1998-08-07 2001-02-20 Motorola, Inc. Electronic circuit and method for automatic frequency control
JP3607097B2 (ja) * 1998-10-29 2005-01-05 アルプス電気株式会社 送信回路
JP4166692B2 (ja) * 2001-07-30 2008-10-15 忠雄 杉田 ノイズリダクション装置およびキャリア再生装置
CN114094998B (zh) * 2022-01-18 2022-04-26 长芯盛（武汉）科技有限公司 用于对电信号的电气状态进行检测的装置和方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3671935A (en) * 1970-05-28 1972-06-20 Honeywell Inf Systems Method and apparatus for detecting binary data by polarity comparison
IT1026581B (it) * 1974-11-27 1978-10-20 Philips Spa Ricevitore per sistema di trasmissione di segnali ad impulsi binari comprendente un circuito per la correzione automatica dei disturbi nellivello di corrente continua
US4695742A (en) * 1983-05-09 1987-09-22 Sangamo Weston, Inc. Charge balance voltage-to-frequency converter utilizing CMOS circuitry
FR2560999B1 (fr) * 1984-03-09 1986-10-31 Camborde Jean Marc Analyseur de bruit dans des cables de transmission de signaux numeriques
US4748419A (en) * 1986-04-28 1988-05-31 Burr-Brown Corporation Isolation amplifier with precise timing of signals coupled across isolation barrier
US4942315A (en) * 1987-06-26 1990-07-17 Tarng Lin J Base point floating cut off wave form differential signal detector circuit
US4965444A (en) * 1988-08-17 1990-10-23 Ransburg Corporation Automatic gain control fiber optica-to-electrical transceiver
IT1228028B (it) * 1988-12-15 1991-05-27 Sgs Thomson Microelectronics Generatore di segnali di pilotaggio per transistori connessi in configurazione a semiponte
US5045800A (en) * 1990-03-23 1991-09-03 Power Integrations, Inc. Pulse width modulator control circuit
JP3064351B2 (ja) * 1990-08-20 2000-07-12 ソニー株式会社 Ｂｓチューナ

Also Published As

Publication number Publication date
JP2845253B2 (ja) 1999-01-13
JPH0638135A (ja) 1994-02-10
US5559836A (en) 1996-09-24
DE69321410D1 (de) 1998-11-12
DE69321410T2 (de) 1999-06-10
EP0579236A1 (de) 1994-01-19

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